Option G G3: Impacts of humans on ecosystems. Calculate the Simpson diversity index for two local communities. See Handout. Analyze the biodiversity of the two local communities using the Simpson Index. See Handout.
DDT is sprayed on crops to control insects. It washes off into rivers and lakes and gets on aquatic plants and phytoplankton (producers) at low comcentrations. Little fish eat these producers and build up higher and higher levels of DDT in their lifetimes (bioaccumulation). In the next trophic level, a medium-sized fish will consume many small fish, concentrating all of the DDT from all of the little fish in their bodies. When birds eat large fish and medium fish then they get all of the DDT from those fish. The concentration has increased at each trophic level--biomagnification.